Waltham DPW...full-stop. They were required to install plastic pop-up posts on the centerline of the town-control roadways @ Elm+Moody in the original ratification of the Quiet Zone waiver from 2006, and did nothing. It's been out-of-compliance for 15 years, and the FRA finally called out the bullshit.
The local municipality. We've learned that in West Medford: MBTA does the gates, the down does the street, which in our case (at Rt 16 and Canal St) is our our centerline reflector-barriers (cricket-paddle style flex posts) I think one time, for about a day they got too battered, the horn came back and the city went to the storeroom and got the replacements
On a high-traffic artery, that's ruled case-by-case. It would be required at Elm/Moody, because without it motorcycles could split the proverbial uprights with impunity and probabilities dictate there'd be enough cheaters trying while the gates are in-process of coming down to result in some damaged gate arms (either that or incidences of re-cycling, as gate machinery is programmed to "wave" up and down if they encounter an obstruction on the way down). It's not required at Beaver St., where a "tri" gate does presently exist on the south side of the crossing to cover the cheat exploit from an abutting driveway bulb-out...but that's a much lower-volume road.
